Restoration of vision in genetically eyeless adult axolotls will be tried by grafting in eyes and optic nerves from normal animals. If the eye can become vascularized quickly enough, it is expected that the sensory retina will either be maintained or will regenerate and send optic nerve fibers into the brain of the host. Whether these will grow into the tectum and establish a normal topographic distribution there will be examined. Induction and formation of postsynaptic junctions in tectal cells which had never received visual input will be studied using Golgi staining and electronmicroscopic techniques. Electronmicroscopy, microspectrophotometry, and histochemistry will be used to compare cells of the eye-forming region of the brains in normal and eyeless mutant axolotls. Factors affecting the crossing or non-crossing of the midline of the brain by optic nerve fibers will be examined by grafting eyes in various locations and at different times into eyeless embryos, larvae, or adults.